WASHINGTON - The State Department began firing more than 1,350 US-based employees on Friday as the administration of President Donald Trump presses ahead with an unprecedented overhaul of its diplomatic corps, a move critics say will undermine US ability to defend and promote US interests abroad.

The layoffs, which affect 1,107 civil service and 246 foreign service officers based in the United States.

"The Department is streamlining domestic operations to focus on diplomatic priorities," an internal State Department notice that was sent to the workforce said. "Headcount reductions have been carefully tailored to affect non-core functions, duplicative or redundant offices, and offices where considerable efficiencies may be found," it added.

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The total reduction in the workforce will be nearly 3,000, including the voluntary departures, according to the notice and a senior State Department official, out of the 18,000 employees based in the United States.

The move is the first step of a restructuring that Trump has sought to ensure US foreign policy is aligned with his "America First" agenda.

"President Trump and Secretary of State Rubio are once again making America less safe and less secure," Democratic senator Tim Kaine from Virginia said in a statement.

Dozens of State Department employees crowded the lobby of the agency’s headquarters in Washington holding an impromptu "clap-out" for their colleagues who have been fired. Dozens of people were crying, as they carried their belongings in boxes and hugged and bid farewell to friends and fellow workers.

Outside, dozens of others were lined up continuing to clap and cheer for them with some holding banners that read, “Thank you America’s diplomats.” Democratic Senator Chris Van Hollen attended the demonstration.

Several offices were set up inside the building for employees who are being laid off to turn in their badges, laptops, telephones and other property owned by the agency.

The offices were marked by posters that read "Transition Day Out Processing". One counter was labeled an "Outprocessing service center" with small bottles of water placed next to a box of tissue. Inside one office, cardboard boxes were visible.

A five-page "separation checklist" that was sent to workers who were fired on Friday and seen by Reuters tells the employees that they would lose access to the building and their emails at 5 pm EDT on Friday.

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Many members of a State Department office overseeing the US resettlement of Afghans who worked for the US government during the 20-year war have also been terminated as part of the overhaul.

'Wrong signal'

Trump in February ordered Secretary of State Marco Rubio to revamp the foreign service to ensure that the Republican president's foreign policy is "faithfully" implemented. He has also repeatedly pledged to "clean out the deep state" by firing bureaucrats that he deems disloyal.

The shake-up is part of an unprecedented push by Trump to shrink the federal bureaucracy and cut what he says is wasteful spending of taxpayer money. His administration dismantled the US Agency for International Aid, Washington's premier aid arm that distributed billions of dollars of assistance worldwide, and folded it under the State Department.

Rubio announced the plans for the State Department shake-up in April, saying the Department in its current form was "bloated, bureaucratic" and was not able to perform its mission "in this new era of great power competition."

He envisioned a structure that he said would give back the power to regional bureaus and embassies and get rid of programs and offices that do not align with America's core interests.

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That vision would see the elimination of the role of top official for civilian security, democracy, and human rights and the closure of some offices that monitored war crimes and conflicts around the world.

The reorganization had been expected to be largely concluded by July 1 but did not proceed as planned amid ongoing litigation, as the State Department waited for the US Supreme Court to weigh in on the Trump administration's bid to hal